Perforating equipments are used for executing transversal perforations in systems for the automatic processing of documents derived from continuous paper forms.
Such systems use high speed printers, in which the cost of print for the customers depends on the number and not on the width of the printed lines. It has brought to provide equipments for processing documents derived from continuous forms having a width double with respect to the width of the component sheets: the form is cut longitudinally into two sections, and thereafter trimmed and transversely cut at the requested dimensions, according to the “two-up” technique.
An equipment for the perforation of two longitudinal sections of a continuous form in movement has been described in the Italian patent application TO 2003A000418, filed on Jun. 4, 2003 and assigned to Tecnau S.r.I. The equipment processes forms up to 520 mm (20½″) and uses two transversal perforating devices arranged one behind the other along the direction of movement. The perforating devices include blades inclined with respect to the direction of movement, contrast rollers synchronous with the movement of the forms and servomechanisms of control for the rotation of the blades and the perforation in synchronism with the velocity of the forms. The equipment operates at high velocity with large possibility of positioning of the perforations in the obtainable documents.
For further saving of costs, printers have been proposed adapted to print documents on continuous forms of over 590 mm, to be longitudinally cut into three longitudinal sections, according to a “three up” technique. However, the transversal perforating devices currently in commerce are not adapted to operate in systems which use printers for continuous forms to be cut into more than two longitudinal sections at the output velocities allowed by the current technologies.